I had a just so-so experience at Jiko, but I'd certainly give it another shot. It wasn't terrible, but I thought it was mediocre for the price. The apps are much more appealing to me than the entrees.
Sanaa is my all time fav WDW restaurant. And Boma was great too. I didn't like everything, but I enjoyed being able to try it all.
Some things to think about: At Boma it's a buffet, so if you want to be served, reconsider. If having lots of options appeals to you, Boma might be a good choice. However, if getting up 10 times with your kids does not appeal to you, you may want to choose something else. As for Jiko and Sanaa, I'd look at the menus to see what appeals to you. I've never had a bad item at Sanaa, but they have a limited kids menu and very few non-exotic options. If you are paying OOP, Sanaa is much more affordable, especially at lunch. A definite bargain to be had. Boma is much pricier and Jiko will be two credits, so there's a lot to think about, but I don't think you can go wrong either way. I don't feel the need to do the same meal at Boma again (Dinner), but I'd go back for breakfast. I'd try Jiko again sometime and I'd go to Sanaa anytime!
It's a great dilemma to have-have a wonderful meal, whatever you choose!